1. Field of the Invention
The present invention relates to an image bearing member unit that includes an image bearing member on which a toner image is formed and a support member supporting the image bearing member and that can be taken out of and put into the main body of an image forming apparatus, a process cartridge including the image bearing member unit, and an image forming apparatus using the image bearing member unit or the process cartridge.
2. Discussion of the Background
It is known that an image bearing member unit including an image bearing member on which a toner image is formed and a support member supporting the image bearing member is used in image forming apparatuses such as a copier, a printer, a facsimile apparatus, or a multi-function apparatus having functions of at least two of these apparatuses. The image bearing member unit can be taken out of and put into main bodies of the image forming apparatuses. When the image bearing member unit has been taken out of respective main bodies of the image forming apparatuses, if the image bearing member of the image bearing member unit is directly exposed to light, the image bearing member is deteriorated. If the image bearing member is touched by a hand or a thing, the surface of the image bearing member may be soiled or damaged.
In order to avoid such problems, for example, Japanese Patent Laid-open Publication No. 2001-337580 proposes an image forming apparatus, in which a shutter is provided to an image bearing member unit. When the image bearing member unit is taken out of the main body of the image forming apparatus, the shutter is moved to a closed position wherein the shutter covers an image bearing member of the image bearing member unit. When the image bearing member unit is put into the main body of the image forming apparatus to be set therein, the shutter is moved back to an opened position wherein the shutter does not cover the image bearing member.
In a known image forming apparatus in which a shutter is provided to an image bearing member unit to cover and uncover an image bearing member of the image bearing member unit as in the image forming apparatus of the above JP Publication, the shutter is supported by a support member of the image bearing member unit to rotate, and in conjunction with an operation of attaching and detaching the image bearing member unit to and from the main body of the image forming apparatus, the shutter is rotated to move to the opened or closed position. When a shutter is configured to rotate to move to opened and closed positions, in order that the shutter is rotated without any trouble, a relatively large space is necessary inside of the main body of an image forming apparatus, so that the size of the main body of the image forming apparatus inevitably increases.